JPWO2013088849A1 - Cutting apparatus and processing method using the same - Google Patents

Abstract

To make it possible to use a certain abnormality detection threshold even in machining passes where the cutting depth changes from moment to moment, set the machining conditions and cut the workpiece with the cutting tool based on the set machining conditions. The cutting tool vibration or cutting force is detected during cutting of the work material, the detected signal is processed and separated into the cutting component signal and the tool vibration component signal, and information on the separated cutting component signal is obtained. And a tool vibration component signal information to calculate a determination index value for determining a state during machining, compare the calculated determination index value with a predetermined determination threshold value, and Calculate new machining conditions including an override amount for the machining conditions set according to the size of the judgment index value, and change the set machining conditions to the calculated new machining conditions to cut the workpiece with the machine tool I made it.

Description

  The present invention relates to a cutting apparatus that performs cutting under conditions that do not cause machining abnormalities by monitoring a machining state during cutting and sequentially changing machining conditions, and a machining method using the same.

  Cutting is a general processing method used for various metal processing, and a cutting blade attached to a rotary tool is cut into a work material and processed into various shapes by removing the material. When machining a part having a complicated shape, the removal amount increases, so that the cutting efficiency, the feed speed, and the tool rotation speed are increased to increase the efficiency.

  When the amount of cutting and the number of rotations of the tool are increased, the force applied to the cutting edge increases, so that processing troubles such as tool vibration, cutting edge wear and breakage are likely to occur. When a processing trouble occurs, the surface roughness of the processed part deteriorates or is damaged, so that the material must be discarded, resulting in a disposal cost. Therefore, a technique for monitoring a machining state and constructing a system capable of changing machining conditions or stopping machining immediately before an abnormality occurs is indispensable.

  Conventionally, as a method for detecting tool vibration, there is known a method for determining that chatter vibration has occurred when an acceleration sensor is attached to a tool or a work material and the signal amplitude exceeds a predetermined value. Japanese Unexamined Patent Publication No. 2000-84798 (Patent Document 1) discloses a method of measuring the vibration amplitude of a tool and changing the tool rotation speed when the vibration amplitude exceeds a preset threshold value.

JP 2000-84798 A

  In a machining system that measures cutting force during cutting and prevents machining abnormalities while changing machining conditions in real time, the tool vibration is described in Patent Document 1 because the vibration amplitude changes as the cutting depth changes. The method of setting the abnormality detection threshold in advance is applicable only when the cutting amount is constant, and cannot be applied when the tool vibration amplitude changes with the change of the cutting amount.

  An object of the present invention is to provide a cutting apparatus and a machining method using the same that can reliably detect an abnormality even in a machining path in which the cutting amount changes every moment.

  In order to solve the above-described problems, in the present invention, when cutting a work material using a cutting tool in a cutting apparatus, the vibration or cutting force of the cutting apparatus is measured to sequentially change the processing conditions. In a machining method using a machining apparatus, a first step of setting a machining condition for cutting the workpiece with the cutting tool, and cutting the workpiece based on the set machining condition A second step of detecting vibration or cutting force of the cutting device and converting it to an electrical signal; a third step of separating the converted electrical signal into the cutting component signal and a tool vibration component signal; A fourth step of calculating a determination index value for determining a machining state during machining with the cutting tool using the information of the separated cutting component signal and the information of the tool vibration component signal; and the calculated determination index value A fifth step of comparing the determination threshold value set in advance to determine whether or not there is an abnormality during the cutting of the workpiece with the cutting tool, the determination result of the presence or absence of the abnormality during the cutting and the setting A sixth step for storing the machining conditions in association with each other, a seventh step for calculating a new machining condition from the magnitude of the calculated determination index value, and the machining conditions set in the first step. And an eighth step of cutting the work material with the cutting tool by changing to the new machining condition calculated in the step, and the determination index calculated in the fourth step in the eighth step Based on the value, the machining method using the cutting device is characterized in that the new machining condition including an override rate with respect to the machining condition set in the first step is set.

  In the present invention, in order to solve the above-mentioned problem, in a processing method using a cutting apparatus, a processing condition for cutting a work material using a cutting tool in the cutting apparatus is set, and the setting is performed. Cutting the workpiece with the cutting tool based on the machining conditions, detecting vibration or cutting force of the cutting device while cutting the workpiece, and processing the detected signal to obtain a cutting component A signal and a tool vibration component signal, and using the information of the separated cutting component signal and the information of the tool vibration component signal, a determination index value for determining a state of machining during machining by the cutting tool is calculated. The calculated determination index value is compared with a predetermined determination threshold value, and a new processing condition including an override rate for the set processing condition according to the magnitude of the determination index value with respect to the determination threshold value Calculate And so cutting the workpiece by the cutting device the serial setting machining conditions by changing to a new machining conditions said calculated.

  Furthermore, in the present invention, in order to solve the above-described problems, a cutting apparatus that sequentially changes machining conditions by measuring vibration or cutting force of the apparatus while cutting a work material using a cutting tool is provided. Machining condition setting means for setting a machining condition for cutting a work material using a tool, and the cutting apparatus for cutting the work material based on the machining conditions set by the machining condition setting means Signal converting means for detecting the vibration or cutting force of the tool and converting it into an electric signal, signal separating means for separating the electric signal converted by the signal converting means into a cutting component signal and a tool vibration component signal, and the signal separating means A determination index calculation means for calculating a determination index value for determining the state of machining during cutting with the cutting tool using the information on the cutting component signal and the information on the tool vibration component signal separated in Step 1, and the determination index In the calculation means An abnormality determination unit that compares the issued determination index value with a preset determination threshold value to determine the presence or absence of abnormality, a determination result of the presence or absence of abnormality determined by the abnormality determination unit, and the processing condition setting unit A storage unit that stores processing conditions in association with each other, and a determination index value calculated by the determination index calculation unit is compared with a predetermined determination threshold value according to the magnitude of the determination index value with respect to the determination threshold value. Machining condition calculation means for calculating a new machining condition including an override rate for the set machining condition, and the machining condition setting means sets the set machining condition during the cutting of the work material. The machining conditions are changed to new machining conditions calculated by the machining condition calculation means.

  Furthermore, in the present invention, in order to solve the above-described problems, when cutting a workpiece using a cutting tool with a cutting apparatus, the vibration or cutting force of the cutting apparatus is measured and the processing conditions are sequentially changed. In the machining method using the cutting device, the amplitude of the vibration of the cutting device derived from the vibration of the cutting tool is derived from the cutting as an index value for determining the state of machining during the machining with the cutting tool. The information based on the value obtained by dividing by the amplitude of vibration of the cutting device is used.

  Furthermore, in the present invention, in order to solve the above-described problems, when cutting a workpiece using a cutting tool with a cutting apparatus, the vibration or cutting force of the cutting apparatus is measured and the processing conditions are sequentially changed. In the processing method using the cutting device, the vibration of the cutting device derived from the vibration of the cutting tool is frequency-converted as an index value for determining the state of processing during processing with the cutting tool, and the side Information based on a value obtained by dividing the lobe amplitude by the main lobe amplitude is used.

  Furthermore, in the present invention, in order to solve the above-mentioned problem, a data input support device that supports data input in a processing device having a function of measuring a cutting state amount accompanying processing for rotating a cutting tool and detecting processing abnormality, A machining condition input unit that presents a library item of machining conditions for machining a workpiece with the cutting tool to the user and receives designation of the library item of machining conditions from the user, and a workpiece with the cutting tool A machining path input unit that presents a machining path library item for machining to the user and receives designation of the machining path library item from the user, and characteristics of the tool for machining the workpiece with the cutting tool A tool / work material property input unit that presents a library item of work material properties to the user and receives specification of the tool property and work material property library items from the user. A library item of a condition for determining a machining abnormality is presented to the user from data obtained by measuring a cutting state amount when the work material is machined by the cutting tool, and the determination is made by the library item of the determination condition from the user. And a determination condition input unit.

  According to the present invention, since a constant abnormality detection threshold can be used even in a machining path in which the cutting depth changes, the abnormality detection accuracy can be improved and the machining accuracy can be improved.

It is a flowchart which shows the processing method of the cutting apparatus of Embodiment 1 of this invention. It is a block diagram which shows the structure of the cutting apparatus which concerns on Embodiment 1 of this invention. It is a block diagram which shows the detailed structure of the cutting force measuring apparatus of the cutting apparatus which concerns on Embodiment 1 of this invention, a cutting condition calculation apparatus, a controller, and a memory | storage part. It is a top view of the work material and cutting tool which show the state in which the work material is being cut. It is a wave form diagram of a vibration signal acquired with a force sensor during cutting of a work material. It is a signal waveform diagram which shows the state which isolate | separated into a cutting component force signal and a tool vibration signal the vibration signal acquired with the force sensor during the cutting of the workpiece. It is a wave form diagram of a cutting component force signal extracted from a vibration signal acquired with a force sensor during cutting of a work material. It is a wave form diagram of a tool vibration signal extracted from a vibration signal acquired with a force sensor during cutting of a work material. It is a wave form diagram which shows the result of carrying out reverse frequency conversion of the cutting component force signal extracted from the vibration signal acquired with the force sensor during the cutting of the workpiece. It is a wave form diagram which shows the result of carrying out reverse frequency conversion of the tool vibration signal extracted from the vibration signal acquired with the force sensor during the cutting of the workpiece. It is a signal waveform diagram explaining another method which isolate | separates into a cutting component force signal and a tool vibration signal the vibration signal acquired with the force sensor during the cutting of the workpiece. It is a graph which shows the relationship between a tool vibration amplitude and a chatter parameter | index value. It is a graph which shows the relationship between the chatter parameter | index value and override rate explaining the method of setting an override rate in steps according to a chatter parameter | index value. It is a graph which shows the relationship between the chatter parameter | index value and override rate explaining the method of setting an override rate continuously according to a chatter parameter | index value. It is a figure for demonstrating the method to set the step width | variety of an override rate, and is a graph which shows the relationship between a tool rotation speed and an axial cutting amount. It is a figure for demonstrating the method to set the upper limit of an override rate, and is a graph which shows the time change of an override rate. It is a flowchart for demonstrating the algorithm which sets an override rate using the graph shown to FIG. 9A. It is a flowchart for demonstrating the algorithm which sets an override rate using the graph shown to FIG. 9B. It is a front view of the input screen which inputs the processing condition setting method in the Example of this invention. It is a figure which shows an example of the file format of the library information in the input screen which inputs the process condition setting method in the Example of this invention. It is a front view of the input screen which inputs the processing path setting method in the Example of this invention. It is a figure which shows an example of the file format of the library information in the input screen which inputs the process path setting method in the Example of this invention. FIG. 16 is a diagram showing an example of file information when “Acquire from file” is selected in “Diameter cutting input method” on the input screen for inputting the machining path setting method shown in FIG. 15. FIG. 16 is a diagram showing an example of file information when “Acquire from file” is selected in “Work material thickness input method” on the input screen for inputting the machining path setting method shown in FIG. 15. It is a front view of the screen which selects the tool characteristic input method or the work material characteristic input method in the Example of this invention. It is a figure which shows an example of the file format of the library information in the input screen which inputs the tool characteristic input method in the Example of this invention, or a workpiece characteristic input method. It is a front view of the screen which inputs the tool specification in the Example of this invention. It is a figure which shows an example of the file format of the library information of the tool specification in the Example of this invention. It is a front view of the screen which inputs the specification of the work material in the Example of this invention. It is a figure which shows an example of the file format of the library information of the specification of the work material in the Example of this invention. FIG. 19 is a screen showing an example of a table displayed when “Acquire from table” is selected as the work material property input method on the input screen for inputting the tool property input method or the work material property input method shown in FIG. 18. . It is a front view of the screen which inputs the determination conditions in the Example of this invention. It is a graph which shows the tool vibration waveform at the time of the cutting start or the cutting end. It is a graph which shows the result of having frequency-converted the waveform of FIG. 26A.

  Hereinafter, an example of an embodiment to which the present invention is applied will be described with reference to the drawings. However, in the following description, the same components are denoted by the same reference numerals, and repeated description is omitted.

  A first embodiment will be described with reference to FIGS. FIG. 2 shows a configuration of a cutting apparatus 500 according to the present embodiment. In this embodiment, a three-axis control machining apparatus will be described as an example, but the number of control axes and the apparatus configuration are not limited thereto. The cutting device 500 holds and moves a housing 501, a machining tool 504, a spindle 503 that rotates the machining tool 504, a spindle stage 502 that moves the spindle 503, a work material 505, and a work material 505. A table 506, a controller 507 for instructing the cutting device 500 to operate, a force sensor 508 built in the table 506, a cutting force measuring device 509 for receiving a signal from the force sensor 508 and measuring a cutting force, and a tool or the like from the storage unit 511 A cutting condition calculation device 510 that obtains information such as material characteristics and a machining path of a work material to plan cutting conditions, and performs machining abnormality determination based on information on the cutting force measured by the cutting force measuring device 509. And an input unit 512 for inputting data such as an abnormality determination threshold value.

  The machining apparatus 500 processes the shape of the work material 505 by rotating the work tool 504, cutting it into the work material 505, and removing it. The machining tool 504 vibrates the machining tool 504, the housing 501 and the like due to the force received from the work material 505. When the amplitude of this vibration increases, the surface roughness of the work surface of the work material 505 decreases, Problems such as breakage of the tool 504 occur.

  Therefore, in this embodiment, a signal from the force sensor 508 built in the table 506 is processed by the cutting force measuring device 509 to obtain a cutting force, and the machining tool 504 and the casing are obtained using the obtained cutting force. The cutting condition calculation apparatus 510 calculates the cutting conditions that detect vibrations such as 501 and suppress the vibrations.

  In this embodiment, the output signal of the force sensor 508 built in the table 506 is used. However, the force sensor is built in the spindle 503, and the output signal of the built-in force sensor, or the acceleration sensor is installed in the table 506 or the spindle stage 502. The output signal of this acceleration sensor or the like can also be used.

  FIG. 3 is a functional block diagram showing the internal configuration of the cutting force measuring device 509, the cutting condition calculating device 510, the controller 507, the storage unit 511, and the input unit 512 of the cutting device 500 as functional blocks. The cutting condition calculation device 510 includes an abnormality determination unit 140 and a condition calculation unit 150.

  The storage unit 511 includes a machining condition history storage unit 181 that stores a history of machining conditions, a chatter determination history storage unit 182 that stores a history of chatter determination results, and material characteristics and dynamic characteristics of the machining tool 504 and the work material 505. , A tool / work material characteristic storage unit 184 that stores a shape, a machining path storage unit 183 that indicates a path for moving the processing tool 504 during processing, and a threshold value that is used to determine a processing abnormality determination threshold. A value storage unit 185 and a signal separation condition setting storage unit 186 that separates signals detected by the force sensor 508 are configured. The machining condition history storage unit 181 and the machining abnormality determination history storage unit 182 are stored in association with each other so that it can be understood which machining condition has occurred when a machining abnormality has occurred. The controller 507 chucks and moves the machining apparatus control unit 101 that controls the operation of the entire cutting apparatus 500, the spindle control unit 102 that controls the operation of the spindle 503 that rotates the machining tool 504, and the work material 505. The table control unit 103 controls the operation of the table 506, and a general technique of a cutting apparatus can be used.

  The cutting force measuring device 509 receives a signal output from the force sensor 508 and measures a cutting force, and a signal separating unit 132 that separates the measured cutting force into a cutting component force and a tool vibration component force. It has. The cutting force measuring device 509 will be described with a configuration in which an output signal from the force sensor 508 is input and processed, but the force sensor 508 may be replaced with a sensor that measures vibration, such as an acceleration sensor, a displacement sensor, or a magnetostrictive sensor.

  The signal separation unit 132 separates the low frequency component and the high frequency component by calculating a moving average value by focusing on the difference in frequency between the cutting component force and the tool vibration component force after frequency conversion. Implements a method to determine the profile of cutting component force using simulation, etc. from the method, material characteristics and dynamic characteristics of the tool / work material, shape information and cutting conditions, and to separate the cutting component force and tool vibration component force by pattern matching Electronic circuit. The separation method is changed by switching circuits according to the separation method calculated by the signal separation condition calculation unit 153, and the threshold value used in the separation also uses the value calculated by the signal separation condition calculation unit 183.

  The abnormality determination unit 140 of the cutting condition calculation device 510 includes a determination index value calculation unit 141 that calculates a determination index value from the cutting component force and the tool vibration component force separated by the signal separation unit 132, and a threshold value for the calculated chatter index value. It is provided with a machining abnormality determination unit 142 that determines the presence or absence of chatter vibration by comparing with a value and determines machining abnormality such as tool wear by comparing the maximum value of cutting component force with another threshold value. .

  The processing abnormality determination unit 142 is an electronic circuit that implements a method for determining the presence or absence of chatter vibration by comparing the calculated chatter index value with the threshold value stored in the threshold value storage unit 185. The determination result is stored in the machining abnormality determination history storage unit 182.

  The condition calculation unit 150 includes a machining condition calculation unit 151 that calculates a machining condition, a threshold value calculation unit 152 that calculates a threshold value used in processing abnormality determination, and a signal separation condition calculation unit 153 that calculates a signal separation condition. It is configured with.

  The machining condition calculation unit 151 acquires the machining conditions set in the past from the machining condition history storage unit 181, acquires the machining abnormality determination result determined in the past from the machining abnormality determination history storage unit 182, and further acquires the tool / cover. Information such as material characteristics, dynamic characteristics, and shapes of the processing tool 504 and the work material 505 is acquired from the cutting material characteristic storage unit 184, processing path information is acquired from the processing path storage unit 183, and the processing conditions to be changed are calculated. Is an electronic circuit. The calculated machining conditions are stored in the machining condition history storage unit 181.

  The threshold calculation unit 152 obtains information such as material characteristics, dynamic characteristics, and shapes of the machining tool 504 and the work material 505 from the tool / work material characteristic storage unit 184, and a threshold setting condition storage unit. The electronic circuit obtains a threshold setting method and the like from 187 and calculates a processing abnormality determination threshold. The threshold value calculated by the threshold value calculation unit 152 is stored in the threshold value storage unit 185. The signal separation condition calculation unit 153 obtains machining conditions from the machining condition history storage unit 181, obtains machining path information from the machining path storage unit 183, and further obtains a machining tool 504 from the tool / work material property storage unit 184. And an electronic circuit that obtains information such as material characteristics, dynamic characteristics, and shape of the work material 505 and calculates signal separation conditions.

  The condition calculation unit 150 can also be implemented by an electronic circuit independent of the cutting apparatus 500 or a program in a computer.

  The input unit 512 includes a machining condition input unit 191, a tool / work material characteristic input unit 192, a machining path input unit 193, and a determination condition input unit 194. The machining condition input unit 191 is an input device that inputs machining conditions such as the spindle rotation speed and stores the machining conditions in the machining condition history storage unit 181. The tool / work material characteristic storage unit 184 is an input device that inputs information such as material characteristics, dynamic characteristics, and shapes of the machining tool 504 and the work material 505 and stores the information in the tool / work material characteristic storage unit 184. . The machining path input unit 193 is an input device that inputs a machining path and a machining order and stores them in the machining path storage unit 183. The determination condition input unit 194 is an input device that inputs a method for calculating a signal separation condition and an abnormality detection threshold value and stores them in the signal separation condition setting storage unit 186 and the threshold setting condition storage unit 187. The input unit 512 can also be implemented by an electronic circuit independent of the cutting apparatus 500 or a program in a computer.

  FIG. 1 shows a processing flow in the present embodiment. First, the machining condition calculation unit 151 of the machining condition calculation device 510 performs machining initial condition derivation (S1), and performs machining initial condition storage (S2) for storing the derived machining initial condition in the machining condition history storage unit 181. . In the machining initial condition derivation (S1), the machining condition calculation unit 151 of the cutting condition calculation device 510 uses the tool / work material characteristic storage unit 184 of the storage unit 511 to determine the material characteristics, dimensions, and motions of the machining tool 504 and the work material 505. Information such as characteristics and machining dimensions is acquired and the machining path and cutting conditions are derived from the result of simulation or from a table stored in advance in the machining path storage unit 183. The machining path is a path for moving the machining tool 504 when the machining tool 504 cuts the work material 505, and is determined along with the diameter cutting amount, the shaft cutting amount, the feed speed, and the like.

  Next, in the machining condition setting (S3), information on the machining path and the cutting condition derived by the machining condition calculation unit 151 of the cutting condition calculation device 510 is transmitted to the processing machine control unit 101 of the controller 507, and the processing machine control unit 101 After setting the machining conditions of the cutting apparatus 500, the machining is started by controlling with the spindle control unit 102 and the table control unit 103 (S4). Next, the cutting force measurement (S5) is performed by the force sensor 508 during processing, and the cutting force signal output from the force sensor 508 is input to the cutting force measuring unit 131 of the cutting force measuring device 509 and processed. Signal separation (S6) is performed in which the signal processed by the measurement unit 131 is received by the signal separation unit 132 and separated into a cutting component force signal and a tool vibration component force signal.

  Next, the cutting component force signal and the tool vibration component force signal separated by the signal separation unit 132 of the cutting force measurement device 509 are input to the determination index calculation unit 141 of the abnormality determination unit 140 of the cutting condition calculation device 510, and this input is performed. Determination index calculation (S7) for calculating a determination index using the cutting component force signal and the tool vibration component force signal is performed. Next, information on the determination index calculated by the determination index calculation unit 141 is input to the processing abnormality determination unit 142, and the determination stored in the threshold storage unit 185 of the storage unit 511 in the processing abnormality determination unit 142 in advance. After carrying out the machining abnormality judgment (S8) for judging the machining abnormality such as tool wear and chatter vibration by extracting the threshold information and comparing it with the judgment index information inputted from the judgment index calculation unit 141, the judgment result Is stored in the processing abnormality determination history storage unit 182 to perform processing abnormality determination result storage (S9).

  Thereafter, the processing machine control unit 101 of the controller 507 performs a processing end determination (S10) for determining whether or not the predetermined cutting has been completed. When it is determined that the processing has been completed, the processing is ended (S11).

  When the processing machine control unit 101 of the controller 507 determines that the processing is not completed in the processing end determination (S10), the processing condition calculation unit 151 of the cutting condition calculation device 510 determines the processing abnormality in the chatter determination storage (S9). The machining condition calculation (S12) for calculating the next machining condition is performed from the chatter determination result stored in the history storage unit 182 and the machining condition stored in the machining condition history storage unit 181 in the machining initial condition storage (S2). The machining condition storage (S13) for storing the calculated condition in the machining condition history storage unit 181 is performed. Next, the controller 507 performs a machining condition change (S14) for setting the control amounts of the spindle control unit 102 and the table control unit 103 based on the machining conditions calculated by the machining condition calculation unit 151. Thereafter, the cutting force measurement (S5) to the machining condition change (S14) are repeatedly performed, and the process is repeated until it is determined that the machining is finished.

  An example of a method for performing signal separation (S6) performed by the signal separation unit 132 of the cutting force measuring apparatus 509 will be described with reference to FIGS. FIG. 4 is a view of a state in which the work material 505 is being processed by the processing tool 504 as viewed from above the cutting apparatus 500. The processing tool 504 has a structure in which a plurality of chips 516 each having a cutting edge formed on a rotating shaft 515 are attached. In the present embodiment, a processing method is shown in which the processing tool 504 is rotated and the chips 516 are cut into the work material 505 to scrape the work material 505. However, the number of the chips 516 attached to the processing tool 504 is illustrated. The number is not limited to two, and may be three or more. Further, it is possible to use a processing method in which the processing tool 504 is fixed and the work material 505 is rotated.

  In FIG. 4, Ft is a force applied from the work material 505 to the chip 516 when the work material 505 is cut with the chip 516 by feeding the work tool 504 in the direction of the tool while rotating in the direction of the arrow. The cutting component force that is a force component in the tangential direction of the machining tool 504 is represented. On the other hand, Fr represents a tool vibration component that is a force component in the radial direction of the machining tool 504 of the force applied from the work material 505 to the tip 516.

  FIG. 5A shows an output signal from the force sensor 508. The force applied to the force sensor 508 is the resultant force of the cutting component force (Ft), which is the force for the chip 516 to scrape the workpiece 505, and the tool vibration component force (Fr) resulting from the tool vibration. The output signal includes a cutting component force signal and a tool vibration component force signal.

FIG. 5B shows a diagram obtained by frequency-converting the output signal from the force sensor 508. The cutting component force is a force when the chip 516 cuts into the work material 505, and has a frequency that is a value obtained by multiplying the tool rotation speed (N) by the number of chips. For example, when the tool rotation speed is 3000 (min ⁻¹ ) and the number of chips is 2, the frequency of the cutting component force is 3000/60 × 2 = 100 (Hz). On the other hand, the frequency of the tool vibration component takes a value near the natural frequency of the machining tool 504. The cutting component force frequency is easily estimated from the tool rotation speed, and generally, the tool vibration component frequency is 10 times or more of the cutting component force frequency, so that the cutting component and the tool vibration component are easily separated from FIG. 5B. be able to.

  The separated results are shown in FIGS. 6A and 6B. 6A shows the frequency of the cutting component force, and FIG. 6B shows the frequency of the tool vibration component force. The results of inverse frequency conversion of these signals are shown in FIGS. 6C and 6D. The output signal from the force sensor 508 shown in FIG. 5A is separated into a cutting component (FIG. 6C) and a tool vibration component (FIG. 6D). Become.

  Another embodiment of the signal separation (S6) performed by the signal separation unit 132 of the cutting force measuring device 509 will be described with reference to FIG. First, the moving average line 520 of the output signal from the force sensor 508 shown in FIG. 5A is calculated. The moving average width is set to be not less than the tool vibration period (T1) and less than the cutting period (T2). The moving average line 520 is a low frequency component and indicates a cutting component force having a low frequency. Next, a process of calculating a difference between the original signal (output signal component from the force sensor 508) and the calculated moving average line 520 is performed. This value (a signal component obtained by subtracting the component of the moving average line 520 from the output signal component from the force sensor 508) is a high-frequency component and indicates a tool vibration component force having a high frequency. Also by this method, it is possible to separate the signal from the force sensor 508 into the cutting component force and the tool vibration component force.

  Further, a cutting component force profile is obtained by using a simulation or the like from the material characteristics, dynamic characteristics, and shape information of the machining tool 504 and the work material 505 stored in the tool / work material characteristic storage unit 184, pattern matching, etc. The signal separation can also be performed by adjusting the waveform of the low frequency component to the cutting force signal by calculating the difference from the cutting force signal and obtaining the high frequency component.

  When obtaining the tool vibration component force, there is a case where the tool vibrates at the start of cutting into the work material and at the end of the cutting, and erroneously determined as chatter vibration. A waveform example at that time is shown in FIG. 26A. Since the beginning and end of cutting are in an unsteady state, it is considered that tool vibration is induced. However, since it is not in a chatter vibration state, the tool vibration is quickly attenuated, and the vibration converges before the next blade cuts. The result of frequency conversion of the waveform of FIG. 26A is shown in FIG. 26B. Another frequency 1303 is generated at a position h [Hz] away from the frequency 1302 of the peak value Va of the tool vibration component force. This is a frequency generated because the tool vibration is damped, and h is approximately equal to the frequency 1301 of the cutting component force. Since the peak value Vb of the frequency 1303 increases as the damping of the tool vibration increases, the damping index is defined as Vb / Va. When the damping index is equal to or greater than the threshold value, it is determined that the damping of the tool vibration is large. Judge that there is no chatter vibration.

  When it is determined that there is no chatter vibration state, the signal separation unit 132 changes the tool vibration magnitude Fc to zero. In the abnormal signal separation, the frequency of the cutting component force and the frequency of the tool vibration component are separated, but the range of each frequency can be acquired from the signal separation condition calculation unit 153. In addition, as an explanation of the signal separation method, the example of separation into the frequency of the cutting component force and the frequency of the tool vibration component force has been described. However, when the work material has low rigidity, for example, a plate-like work material is cut. In some cases, the vibration of the work material may be larger than the tool vibration, and the frequency of the work material vibration may be used instead of the frequency of the tool vibration component.

  Next, an example of a method for carrying out the determination index calculation (S7) executed by the determination index calculation unit 141 of the abnormality determination unit 140 will be described. The magnitude of the tool vibration component force varies depending on the machining conditions. For example, even if the amplitude of the tool vibration is the same, the area of contact between the tip 516 and the work material 505 is doubled when the amount of axial cut is doubled, so the tool vibration component force applied to the processing tool 504 is also doubled. It becomes. Therefore, when determining the presence or absence of chatter vibration from the magnitude of the tool vibration component force, a certain threshold value cannot be used.

Therefore, as in the case of the tool vibration component force, an index (chatter index) obtained by normalizing the tool vibration component force with a cutting component force whose size depends on the machining conditions is introduced. The value of the chatter index is calculated by Equation 1.
Chatter index value = Fv / Fc (Expression 1)
Here, Fc is the magnitude of the cutting component force (corresponding to Fc in FIG. 6C), and Fv is the amplitude of the tool vibration component force (corresponding to Fv in FIG. 6D).

FIG. 8 shows a simulation result of the relationship between the tool vibration amplitude and the chatter index value.
In FIG. 8, for example, ■ indicates the relationship of the chatter index value to the tool vibration amplitude when machining is performed under the condition that the shaft depth is 0.4 mm and the rotational speed of the machining tool 504 is 3120 rpm. According to FIG. 78, there is a linear relationship between the tool vibration amplitude and the chatter index value, and the data are arranged on the same straight line even if the machining conditions change. Since the tool vibration amplitude and the chatter index value have a unique relationship, the same threshold value can be used regardless of the machining conditions.

  Furthermore, by using the relationship of FIG. 8, the threshold value of the chatter index value can be obtained from the allowable tool vibration amplitude.

  Further, since there is a linear relationship between the tool vibration amplitude and the chatter index value, the machining condition calculation unit 151 determines the machining condition by specifying the allowable tool vibration amplitude in the derivation of the machining initial condition in S1. The shaft cut amount is set based on the relationship of the chatter index value with respect to the tool vibration amplitude as shown in FIG. 8 stored in the history storage unit 181.

  In the processing abnormality determination (S8), the processing abnormality determination unit 142 compares the chatter index value calculated by the determination index calculation unit 141 with the determination index calculation (S7) and the threshold value preset in the threshold storage unit 185. Based on this, the presence or absence of chatter vibration is determined. Further, the presence / absence of machining abnormality such as tool wear is determined by comparing the maximum value of the cutting component force signal with a preset machining abnormality determination threshold value.

  An example of the machining condition calculation (S12) executed by the machining condition calculation unit 151 of the condition calculation unit 150 is shown in FIGS. The cutting apparatus 500 can dynamically control the machining conditions by multiplying the initially set machining conditions by an override rate. As parameters for multiplying the override rate, there are generally a spindle rotation speed and a tool feed speed, and the override rate can be changed within a range of 0 to 200%. Here, a method of changing the machining condition by changing the override amount will be described as an example, but a method of directly changing the machining condition may be used.

9A and 9B show conversion graphs of the override rate applied from the chatter index value.
In FIG. 9A or 9B, the chatter determination threshold value is set to c1. When the chatter index value exceeds c1, the machining abnormality determination unit 142 determines that chatter has occurred in the machining abnormality determination (S8), and the machining condition calculation unit 151 calculates the override change amount in the machining condition calculation (S12) process. In the machining condition change (S14) step, the machining tool control unit 101 of the controller 507 controls the spindle control unit 102 and the table control unit 103 on the basis of the override rate calculated by the machining condition calculation unit 151. The override ratio is changed by driving 504 and the table 506. At this time, in the machining condition calculation (S12), the machining condition calculation unit 151 obtains the override rate from FIG. 9A or FIG. 9B, and calculates the new override rate by multiplying the current override rate. Further, the machining condition is calculated by multiplying the calculated new override rate by the initial setting value of the machining condition.

  When the chatter index value calculated by the determination index calculation unit 141 greatly exceeds the chatter determination threshold value c1, the override rate is increased. When the excess index value is small, the override rate is decreased to quickly chatter vibration. Can be converged. Further, when the chatter index value is smaller than the threshold value c2, a positive override rate is set, and control is performed to further increase the machining efficiency. At this time, chattering of control can be prevented by setting the override ratio 0% between the chatter index values c1 and c2. A positive override rate is set such that a large change rate is set when the chatter index value is significantly below c2, and a small change rate is set when close to c2.

  Although FIG. 9A shows an example in which the override rate is changed stepwise, a straight line or a curved line can be used as shown in FIG. 9B. In particular, in the case of the curve 522 in FIG. 9B, the rate of change is small where the chatter index value is close to c1 or c2, and there is an effect that chattering of control can be further prevented.

FIG. 10 shows a stability limit diagram regarding the relationship between the amount of shaft cutting and the tool rotation speed under general cutting conditions. In FIG. 10, the condition below the stability limit line 530 is a stable condition in which chatter vibration does not occur, and the condition above the stability limit line 530 indicates that chatter vibration is generated and unstable machining is performed. The stability limit line 530 periodically takes a peak value, and the peak position is expressed by the following equation (2) when the tool natural frequency is f0 and the number of the chips 516 is N.
Peak position = 60 · f0 / (N · n) (Equation 2)
Here, n is an integer of 1 or more.

  As one method for increasing the machining efficiency, a method of increasing the amount of removal per unit time by increasing the shaft cutting amount is effective. In order to increase the amount of shaft cutting without generating chatter vibration, it is effective to use the machining conditions at the peak position of the stability limit line 530 (for example, point f in FIG. 10). Accordingly, in the machining initial condition derivation (S1), the machining conditions can be derived by calculating FIG. 10 using simulation or the like. However, because the stability limit line 530 includes an error due to an error such as a material characteristic or a shape dimension of the processing tool 504 or the work material 505, the derived condition is not always optimal. Therefore, the machining conditions are guided to the peak position of the stability limit line 530 using the method described in FIGS. 9A and 9B. At this time, the step width ST of the override rate in FIG. 9A is preferably set to be about a fraction (for example, 1/5 or less) of the peak position interval PW shown in the graph of FIG.

A method for determining the upper limit of the override amount will be described with reference to FIG. 11 in order not to use again the override amount in which chatter vibration has occurred. FIG. 11 is a diagram showing the change over time of the override rate when the override change rate is determined using FIG. 9A. Machining is started under the initial machining conditions, and from time 0 to T3, it is determined that chatter vibration has not occurred, so the override rate becomes positive and the override rate increases. When the override rate increases, chatter vibration is likely to occur. When the chatter index value exceeds the determination threshold (c1 in FIG. 9A or 9B), it is determined that chatter vibration has occurred.
The override rate v3 at this time is stored.

  When the processing abnormality determination unit 142 determines that chatter vibration has occurred, the processing condition calculation unit 151 changes the processing condition so as to reduce the override rate. If the machining abnormality determination unit 142 determines that chatter vibration has not recurred after a predetermined time has elapsed, the machining condition calculation unit 151 changes the machining condition to increase the override rate, but chatter vibration occurs. The upper limit is a value smaller than the override rate v3 stored in the machining condition history storage unit 181 (for example, 90% of p3). Thus, stable machining can be realized by avoiding the use of the condition that once generated chatter vibration.

  In FIG. 11, since chatter vibration is detected again at T4, the override rate at which chatter vibration is detected is stored again as v4, and the override rate is decreased so as to suppress chatter vibration. If chatter vibration has not recurred after a certain period of time, the override rate amount is increased again and reaches 90% of the value of v4 (v5) at T5, so the increase in the override rate amount is stopped.

  FIG. 12A shows an algorithm for realizing the control of FIG. 9A. First, the initial value of the override rate (OV) and override change rate (δOV) is set to 100, and the maximum value that can be taken by the override rate is set to the upper limit value (OV_c) of the override rate (S1101). A chatter index value is calculated (S1102). Next, the chatter index value calculated by the determination index calculation unit 141 is compared with the threshold c1 in the machining abnormality determination unit 142 (S1103), and when the chatter index value is equal to or greater than the threshold c1 (Yes in (S1103)). In this case, it is determined that chatter vibration has occurred, and the determination result and the chatter index value calculated by the determination index calculation unit 141 are stored in the machining abnormality determination history storage unit 182. The machining condition calculation unit 151 determines a value in a flow that branches the step-like override change rate setting condition shown in FIG. 9A according to the size of the chatter index value.

  That is, the machining condition calculation unit 151 determines whether or not the chatter index value stored in the machining abnormality determination history storage unit 182 is smaller than c5 (S1104). If it is smaller (Yes), the override change rate (δOV) is set to p4. Setting is performed (S1105). If the chatter index value is larger than c5 (No in (S1104)), it is determined whether the chatter index value is smaller than c6 (S1106), and if it is smaller (Yes), the override change rate (δOV) is set to p3. It sets (S1107). When the chatter index value is larger than c6 (in the case of No in (S1106)), it is determined whether the chatter index value is smaller than c7 (S1108), and when it is smaller (Yes), the override change rate (δOV) is set to p2. Set (S1109). If the chatter index value is larger than c7 (No in (S1108)), the chatter index value is set to c1 (S1110).

  After the override change rate (δOV) is determined, the machining condition calculation unit 151 substitutes the current override rate for the override upper limit value to obtain a new upper limit value (S1111). Further, the current time (t) is stored in Tc (S1112). Next, a new override amount is calculated by multiplying the current override rate (OV) by the override change rate (δOV) (S1113) and stored (S1114). The stored override rate is used to calculate new machining conditions.

  On the other hand, when the chatter index value is less than c1 (in the case of No in (S1103)), it is determined whether the chatter index value is greater than c2 (S1121), and when it is larger (in the case of Yes in (S1121)). The override rate is set to 100 (S1122). If smaller than c2 (No in (S1121)), it is determined that chatter has not occurred, and it is determined whether the difference between the current time (t) and the stored Tc is equal to or greater than T1 (S1123). This is to determine the elapsed time from the last occurrence of chatter. When the elapsed time (t-Tc) is shorter than T1 (in the case of No in (S1123)), the override change rate is set. 100 (S1122).

  On the other hand, when a time equal to or longer than T1 has elapsed (Yes in (S1123)), it is determined that chatter has been suppressed. When it is determined that chatter has been suppressed, the value is determined by a flow that branches the step-like override change rate setting condition shown in FIG. 9A according to the size of the chatter index value.

  That is, the machining condition calculation unit 151 determines whether the chatter index value stored in the machining abnormality determination history storage unit 182 is larger than c3 (S1124), and if it is larger (Yes in (S1124)), the override change rate (ΔOV) is set to p5 (S1125). On the other hand, when the chatter index value is smaller than c3 (No in (S1124)), it is determined whether the chatter index value is larger than c4 (S1126), and when it is larger (Yes in (S1126)), it is overridden. The rate of change (δOV) is set to p6 (S1127). On the other hand, when the chatter index value is smaller than c4 (No in (S1126)), the override change rate (δOV) is set to p7 (S1128).

  Next, a new override rate is calculated by multiplying the current override rate (OV) by the override change rate (δOV) (S1113) and stored in the machining condition history storage unit 181 (S1114). The override rate stored in the machining condition history storage unit 181 is used by the machining condition calculation unit 151 to calculate a new machining condition. The above flow is repeatedly executed until the machining of the work material 505 is completed.

  FIG. 12B shows an algorithm for realizing the control of FIG. 9B. The point which calculates | requires an override change rate differs from the flow demonstrated in FIG. 12A that the function of a chatter parameter | index is.

  First, the initial values of the override rate (OV) and override change rate (δOV) are set to 100, and the maximum value that can be taken by the override rate is set to the upper limit value (OV_c) of the override rate (S1151). A chatter index value is calculated (S1152).

  The machining abnormality determination unit 142 determines whether the calculated chatter index value is equal to or greater than c1 (S1153), and the determination result is stored in the machining abnormality determination history storage unit 182 together with the chatter index value.

  When chatter index value is greater than or equal to c1 (in the case of Yes in (S1153)), assuming that chatter has occurred, the machining condition calculation unit 51 sets the function f of the chatter index as an override change rate (δOV) (S1154), The current override rate (OV) is set as the upper limit value (OV_c) of the override rate (S1155), and the current time (t) is stored in Tc (S1156). Next, a new override amount is calculated by multiplying the current override rate (OV) by the override change rate (δOV) (S1157) and stored (S1158). The stored override rate is used to calculate new machining conditions.

  On the other hand, if it is determined in S1153 that the chatter index value is not greater than c1 (No in (S1153)), it is determined whether the chatter index value is greater than c2 (S1161), and the chatter index value is greater than c2. If it is determined that it is large (Yes in (S1161)), the machining condition calculation unit 51 sets the override change rate (δOV) to 100 (S1162). If the chatter index value is less than c2 (No in (S1161)), it is determined whether the difference between the current time (t) and the stored Tc is equal to or greater than T1 (S1163). This is to determine the elapsed time from the time when chatter last occurred. When the elapsed time (t−Tc) is shorter than T1 (in the case of No in (S1163)), the override change rate ( (δOV) is set to 100 (S1162).

On the other hand, when the time equal to or longer than T1 has elapsed (in the case of Yes in (S1163)), it is determined that there is room for chatter and the function g is set in the override change rate (δOV) (S1164). When the chatter index value is smaller than c1 and larger than c2, the override change rate is set to 100 in S1162 to prevent chattering.
Details of the input unit 512 shown in FIG. 3 will be described with reference to FIGS. The input unit 512 includes a machining condition input unit 191, a machining path input unit 193, a tool / workpiece material characteristic input unit 192, and a determination condition input unit 194.

  In the machining condition input unit 191, FIG. 13 is a schematic diagram illustrating an example of an input screen 1001 for inputting a machining condition setting method. FIG. 14 is a diagram illustrating an embodiment of the file format of the library information of items displayed on the input screen 1001 illustrated in FIG. 13, and is data stored in the storage unit 511. The library information corresponding to the input screen 1001 includes, for example, a library number 1005 and library items 1006 such as a spindle rotation speed input method. Display items 1002 are displayed on the input screen 1001 in FIG. 13 based on the library information in FIG. 14, and a condition to be used for each item is selected by pressing a radio button 1003. After selecting all items, pressing the enter button 1004 terminates the input and stores the selected items in the machining condition history storage unit 181.

  When “fixed value input” is selected in the spindle rotation speed input method displayed on the input screen 1001 shown in FIG. 13, the value input in the input field 1010 is used as the spindle rotation speed, and the signal separation unit 132 is used. Extract the cutting force component with. When “Acquire from device” is selected, information on the spindle rotation speed acquired from the spindle control unit 102 of the controller 507 is used. Further, when “Acquire from program” is selected, information on the spindle rotation speed of the program stored in the machining apparatus 500 or the controller 507 is acquired. In general, the machining program is composed of several steps, and it is desirable to acquire information on the spindle rotation speed for each step.

  In the machining path input unit 193, FIG. 15 is a schematic diagram showing an example of an input screen 1101 for inputting a machining path setting method. FIG. 16 is a diagram showing an embodiment of a file format of library information of items displayed on the input screen 1101 shown in FIG.

  When “Acquire from file” is selected in the field of diameter cutting amount input method displayed on the input screen 1101 shown in FIG. 15, the file information shown in FIG. 17A is acquired from the specified file. The file information includes, for example, a library number 1107, a library first item 1108, and a library second item 1109. By specifying the machining pass number or program step number as the first library item, and by specifying the diameter cut amount as the second library item, the diameter cut amount corresponding to each machining pass or each program step number is associated. Saved.

  In addition, when “acquire from file” is selected in the work material thickness input method column displayed on the input screen 1101 shown in FIG. 15, the file information shown in FIG. 17B is acquired from the specified file. By specifying the pass number or program step number as the first library item in the file information, and specifying the work material thickness as the second library item, the workpiece corresponding to each pass or program step number is specified. Material thickness can be associated and stored.

  In the tool / work material characteristic input unit 192, FIG. 18 is a schematic diagram illustrating an example of an input screen 1201 for selecting a tool / work material characteristic input method. FIG. 19 is a diagram showing an embodiment of a file format of the library information of items displayed on the input screen 1201 shown in FIG. The library information corresponding to the input screen 1201 is acquired from, for example, a library number 1205, a library first item 1206 for specifying an input target such as a tool property input method and a workpiece property input method, a natural frequency input, and a table. A library second item 1207 for designating a data input method such as the above is included. Display items 1202 are displayed on the input screen 1201 in FIG. 18 based on the library information in FIG. 19, and a condition to be used for each item is selected by pressing a radio button 1003. After selecting all the items, pressing the enter button 1004 terminates the input, and the selected items are stored in the tool / work material characteristic storage unit 184.

  When “input natural frequency” is selected in the column of the tool characteristic input method on the display screen 1201 shown in FIG. 18, the lower limit value and upper limit value, or the median value and range of the frequency are entered in the input field 1010. Specifies the frequency range to be used for signal separation. The same applies when “input natural frequency” is selected in the column of the work material characteristic input method.

  The details when “Calculate from tool specifications” is selected in the column of the tool characteristic input method will be described with reference to FIGS. FIG. 20 is a schematic diagram showing an example of the tool specification input screen 1021. FIG. 21 is a diagram showing an embodiment of a file format of the library information of items displayed on the input screen 1021 shown in FIG. The library information includes, for example, a library number 1025 and a library item 1026 for designating an input target of tool specifications such as a tool length and a tool diameter.

  Details of the case where “Calculate from work material specifications” is selected in the work material property input method column on the display screen 1201 shown in FIG. 18 will be described with reference to FIGS. FIG. 22 is a schematic diagram showing an example of the work material specification input screen 1031. FIG. 23 is a diagram illustrating an embodiment of a file format of the library information of items displayed on the input screen 1031 illustrated in FIG. When transitioning to the input screen 1031, information is input from the file describing the library information in FIG. 22 and displayed. The library information includes, for example, a library number 1035 and a library item 1036 for designating an input target of work material specifications such as a work material shape model and work material composition.

  Details of the case where “Acquire from table” is selected in the column of the work material property input method on the display screen 1201 shown in FIG. 18 will be described with reference to FIG. FIG. 24 shows information described in the table. The library number 1045, the library first item 1046 for designating the machining path, and the library second item 1047 for designating the natural frequency of the work material in each machining path are shown. included. The table information is stored in a file and is read when “Get from table” is selected.

  Details of the determination condition input unit 194 will be described with reference to FIG. FIG. 25 is a schematic diagram illustrating an example of a determination condition input screen 1211. In the signal separation usage data column, one of the selection items for determining whether to use the tool characteristics, the work material characteristics, or the tool characteristics and the work material characteristics as data used for the signal separation is selected. In the column of the abnormality detection threshold setting method, one is selected from the selection items of inputting a fixed value or calculating by simulation. In the attenuation determination column, there is a check box 1053 for selecting whether to execute or not, and it becomes effective when checked. The threshold value used for attenuation determination is the value input in the input box 1054.

  By pressing the decision button 1004 after selecting each item, the items set in “signal separation usage data” and “attenuation determination” are stored in the signal separation condition setting storage unit 186, and “anomaly detection threshold setting method” ”Is stored in the threshold setting condition storage unit 187.

  Details of the signal separation condition calculation unit 153 will be described. Items calculated by the signal separation condition calculation unit 153 are the frequency of the cutting component force and the frequency of the tool vibration or the frequency of the workpiece vibration. As described above, the frequency of the cutting component force may be a tool rotation speed stored in the machining condition history storage unit 181 or a value obtained by multiplying the tool rotation speed acquired from the controller 507 by the number of blades. As a method for calculating the frequency of the tool vibration, a method stored in the signal separation condition setting storage unit 186 is used. For example, when “input of natural frequency” is selected, the input value is used as the frequency of the cutting component force. When “Calculate from tool specifications” is selected, a frequency calculated by a mathematical expression or simulation from the tool length, the tool diameter, and the tool rigidity can be used.

  As a method for calculating the frequency of the workpiece vibration, a method stored in the signal separation condition setting storage unit 186 is used. For example, when “input of natural frequency” is selected, the input value is used as the frequency of the cutting component force. In addition, when “calculate from work material specifications” is selected, a frequency calculated by a mathematical formula or simulation from the shape model, the work material rigidity, the fixed jig model, and the jig rigidity can be used.

  The frequency stored in the signal separation condition setting storage unit 186 is used to determine whether the tool vibration frequency or the workpiece vibration frequency is used. At this time, when the option of using a plurality of frequencies is selected (for example, tool vibration and workpiece vibration), after calculating the respective frequencies and amplitudes, the larger amplitude may be selected.

  According to the present embodiment, the occurrence of chatter vibration can be determined with a constant threshold value regardless of the machining conditions, so that the threshold value can be set appropriately and abnormality detection accuracy is improved. In addition, stable machining can be performed under conditions immediately before chatter vibration occurs, and highly efficient machining can be realized.

  The invention made by the present inventor has been specifically described based on the embodiment of the invention. However, the invention is not limited to the embodiment of the invention, and changes are made without departing from the scope of the invention. Of course, it is possible.

  501 ... Case 502 ... Spindle table 503 ... Spindle 504 ... Machining tool 505 ... Work material 506 ... Table 507 ... Controller 516 ... Chip 515 ... Rotation axis.

Claims (18)

  A cutting method using a cutting device that measures vibration or cutting force of the cutting device and sequentially changes processing conditions when cutting a work material using a cutting tool in the cutting device, A first step of setting a machining condition for cutting the workpiece with a cutting tool, and vibration or cutting force of the cutting device during cutting of the workpiece based on the set machining condition A second step of detecting the signal and converting it into an electric signal, a third step of separating the converted electric signal into a cutting component signal and a tool vibration component signal, information on the separated cutting component signal and a tool vibration component A fourth step of calculating a determination index value for determining a state of processing during processing with the cutting tool using the information of the signal, and the calculated determination index value and a predetermined determination threshold value. Compare and turn off A fifth step of determining presence / absence of abnormality during cutting of the workpiece with a tool, and a sixth step of storing the determination result of presence / absence of abnormality during cutting and the set processing conditions in association with each other; The seventh step of calculating a new processing condition from the calculated determination index value and the processing condition set in the first step are changed to the new processing condition calculated in the seventh step. An eighth step of cutting the workpiece with a cutting tool, and the machining set in the first step based on the determination index value calculated in the fourth step in the eighth step A machining method using a cutting apparatus, characterized in that the new machining conditions including an override rate for the conditions are set.   In the third step, the electrical signal is frequency-converted, and the cutting component force signal and the tool vibration component force signal are separated from the machining condition information stored in advance and the natural frequency of the machining tool. A processing method using the cutting apparatus according to claim 1.   In the third step, a moving average value of the electric signal is calculated, a difference between the electric signal and the moving average value is calculated, the moving average value is used as a cutting component force signal, the electric signal and the moving average. The machining method using the cutting apparatus according to claim 1, wherein a difference in values is used as a tool vibration component signal. Set the processing conditions to cut the work material using the cutting tool in the cutting device,
Cutting the work material with the cutting tool based on the set processing conditions,
Detecting the vibration or cutting force of the cutting device during cutting of the work material;
The detected signal is processed and separated into a cutting component signal and a tool vibration component signal,
Using the information of the separated cutting component signal and the information of the tool vibration component signal to calculate a determination index value for determining the state of machining during machining with the cutting tool;
The calculated determination index value is compared with a preset determination threshold value, and a new machining condition including an override rate for the set machining condition is calculated according to the magnitude of the determination index value with respect to the determination threshold value And
A machining method using a cutting apparatus, wherein the set machining condition is changed to the calculated new machining condition and the workpiece is cut by the cutting apparatus.   The information of the ratio between the magnitude of the separated cutting component signal and the magnitude of the tool vibration component signal is used as a determination index value for judging a machining state during machining with the cutting tool. Or the processing method using the cutting apparatus of 4.   When the calculated determination index value is larger than the preset determination threshold value, an override rate for the set machining condition is set to be smaller than 100% as the new machining condition, and the calculated determination index value is 5. The cutting process according to claim 1, wherein an override rate for the set machining condition is set to be larger than 100% as the new machining condition when it is smaller than a predetermined determination threshold by a predetermined amount or more. A processing method using an apparatus.   The override rate for the set machining condition is set to 100% as the new machining condition when the calculated judgment index value is smaller than a predetermined threshold value within a predetermined amount. A processing method using the cutting apparatus according to 1 or 4.   5. The machining using the cutting apparatus according to claim 1, wherein the override rate is set at a larger change rate as the absolute value of the difference between the determination index and the determination threshold value is larger. Method.   A cutting device that sequentially changes machining conditions by measuring vibration or cutting force of a device while cutting a workpiece using a cutting tool, for cutting the workpiece using the cutting tool. A machining condition setting means for setting a machining condition on the workpiece, and an electrical signal obtained by detecting vibration or cutting force of the cutting device that is cutting the workpiece based on the machining conditions set by the machining condition setting means. Signal converting means for converting, signal separating means for separating the electric signal converted by the signal converting means into a cutting component signal and a tool vibration component signal, information on the cutting component signal separated by the signal separating means and a tool vibration component A determination index value calculating means for calculating a determination index value for determining a state of machining during cutting with the cutting tool using signal information, and a determination index value calculated in advance by the determination index calculation means Judgment An abnormality determination means for comparing the difference value with the abnormality determination means, a storage means for storing the determination result of the presence or absence of abnormality determined by the abnormality determination means and the machining conditions set by the machining condition setting means in association with each other; The determination index value calculated by the determination index calculation means is compared with a predetermined determination threshold value, and a new value including an override rate for the set machining condition according to the size of the determination index value with respect to the determination threshold value A machining condition calculation unit that calculates a machining condition, and the machining condition setting unit changes the set machining condition to a new machining condition calculated by the machining condition calculation unit while cutting the workpiece. The cutting device characterized by performing.   The signal separating means converts the frequency of the electrical signal, and uses the information obtained by frequency-converting the electrical signal, machining condition information stored in advance, and information on the natural frequency of the machining tool as a cutting component. The cutting apparatus according to claim 9, wherein the cutting device is separated into a force signal and a tool vibration component force signal.   The signal separation means calculates a moving average value of the electric signal, calculates a signal difference between the electric signal and the calculated moving average value, uses the calculated moving average value as a cutting component force signal, and the calculated signal. The cutting apparatus according to claim 9, wherein the difference is output as a tool vibration component signal.   The machining condition calculation means sets an override rate for the set machining condition as 100% as the new machining condition when the calculated determination index value is smaller than a predetermined threshold value within a predetermined amount. The cutting apparatus according to claim 9.   The cutting apparatus according to claim 9, wherein the machining condition calculation unit uses a larger override rate as the absolute value of the difference between the determination index and the determination threshold value is larger.   A cutting method using a cutting device that measures vibration or cutting force of the cutting device and sequentially changes processing conditions when cutting a work material using a cutting tool in the cutting device, As an index value for determining the state of processing during the cutting with the cutting tool, the vibration amplitude of the cutting device derived from the vibration of the cutting tool is divided by the amplitude of vibration of the cutting device derived from cutting. A processing method using a cutting apparatus characterized by using information based on values obtained in this manner.   A cutting method using a cutting device that measures vibration or cutting force of the cutting device and sequentially changes processing conditions when cutting a work material using a cutting tool in the cutting device, As an index value for determining the state of machining during machining with a cutting tool, the vibration of the cutting device derived from the vibration of the cutting tool was frequency-converted and obtained by dividing the side lobe amplitude by the main lobe amplitude The processing method using the cutting device characterized by using the information based on a value. A data input support device for supporting data input in a processing device having a function of measuring a cutting state amount accompanying processing for rotating a cutting tool and detecting processing abnormality,
A processing condition input unit that presents a library item of processing conditions for processing a workpiece with the cutting tool to the user and receives specification of the library item of processing conditions from the user,
A processing path input unit that presents a processing path library item for processing a workpiece with the cutting tool to the user and receives specification of the processing path library item from the user;
Library items of tool characteristics and work material characteristics for processing the work material with the cutting tool are presented to the user, and the user specifies the library characteristics of the tool characteristics and work material characteristics from the user. Tool / work material characteristics input section,
A library item of a condition for determining a machining abnormality is presented to the user from data obtained by measuring a cutting state amount when the work material is machined by the cutting tool, and the determination is made by the library item of the determination condition from the user. A judgment condition input section;
A data input support device comprising: 17. The data input support device according to claim 16, wherein a method for separating the signal of the cutting state quantity is changed according to an input item selected by the determination condition input unit. The data input support device according to claim 16, wherein a calculation method of an abnormality detection threshold value for determining the processing abnormality is changed according to an input item selected by the determination condition input unit.

Images